How to Recharge a Car Battery?

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on November 20th, 2024

Reading Time: 7 minutes
Summary
  • Before you start charging using a battery charger, make sure your battery terminals are clean. There will be dirt, crud, or a build-up of sulfur on your terminals. Ensure your battery doesn’t have leaks or smoke coming out.
  • If you have to resort to a jump-start, you’ll need jumper cables and another car. It’s important not to let the clamps touch each other.
  • There’s a specific order when it comes to connecting the two batteries using the jumper cables. Make sure to follow this process for your own safety. Make the final jumper cable connection to a good ground point (unpainted) on the dead battery car’s engine rather than the negative battery cable.

When a car battery dies, you can attribute it to one of the following reasons: either you left your headlights on for too long, used your car accessories excessively, or your charging system is failing for some reason that can range from a bad alternator to poor connections to a slipping belt.

So, for the record, do car batteries recharge? Well, your battery is built to last for four to six years. So unless it suffers from serious corrosion or leakage, a recharge will do to keep it going once it stops functioning.

The best way to recharge the battery is to get the car started and drive it for about 30 minutes. The alternator (if working properly) charges the battery better, safer, and faster than any other method.

That being said, if you need to charge the battery without driving the car and letting the alternator do the job, using a charger isn’t a bad idea as long as you do it right.

Caution: Always wear eye protection when working around batteries. There’s a risk of explosion that must be taken seriously.

The best way to recharge the battery is to get the car started and drive it for about 30 minutes.

Richard McCuistian, ASE Certified Master Automobile Technician

Inspection, Preparation, and Charge Time

Step 1: First, remove, then clean the battery cables, clean the terminals and the posts (or side terminals on some GM vehicles) on the battery.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: If the battery has side terminals, they need to be cleaned and you might consider replacing the bolt that connects the side terminals to the battery on the GM platforms that use those.

You might need to replace the cable or terminal if one of them has been dissolved by the acid.

Again, besides your car battery charger, it helps to also have a pair of safety goggles, rubber gloves, baking soda, water, and a cloth at your disposal. It doesn’t hurt to buy some aerosol battery terminal cleaner and protector. Get some heavy-duty paper towels, too, and maybe a plastic brush.

If the cables look this bad (see photo), a pressure washer is the best way to clean them, but the battery terminal cleaner will work. | Image Source: Richard McCuistian

Step 2: Select a charge setting (if you have a large, heavy charger that will charge the battery as rapidly as possible without overheating it).

Make sure the battery doesn’t have leaks or smoke coming out while charging. If smoke is coming out without charging, replace the battery.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: If your charger doesn’t have a volt meter, connect a DVOM to the battery while you’re charging it and monitor the voltage after charging the battery on fast charge for 5 minutes (if you have a fast charger). If the voltage goes above 15.5 volts while fast charging, the battery is sulfated and will need replacing. Plates are coated with sulfur.

Read your battery charger instructions thoroughly. You need to know whether your car has auto shut-off and fast charging features or manual shut-off and slow charging features. Take note of this as it is important in correctly using your car battery charger.

Note that if yours is a glass mat battery it cannot be charged rapidly without destroying the battery.

How to Recharge a Battery

After inspecting and preparing, you’re ready to recharge.

Step 1: Give sufficient distance between the charger and your battery. Never let them get too close to each other.

Step 2: Remove your battery caps to allow the gasses to escape

Step 3: Identify your terminals: a red or a plus sign means positive and a black or a minus sign stands for negative.

Step 4: Attach the positive charger clamp to the positive battery terminal and the negative charger clamp to the negative battery terminal.

Step 5: Plug and turn on your charger.

So how long to charge a battery? The standard charging time for a full batt is 24 hours for trickle charging.

Jump-start

In the event that you find yourself in the middle of the road and there’s no electric outlet near you, the only option you have is to jumpstart your car using another car.

Things you need are just the same with those mentioned above, but instead of a charger, you’ll need jumper cables, a jumper box, and a functioning car.

Step 1: Inspect the batteries of both cars. Clean the terminals as needed.

Step 2: Make sure the cars have proper distance between them before proceeding; remember to keep them close enough to each other but never in contact.

Step 3: Before attaching the jumper cables, make sure, too, that the engines of both cars are not running.

Step 4: When it comes to working with jumper cables, it’s important not to let the clamps touch each other. In addition, the order of this process is crucial so it’s best to follow the steps carefully. Begin by attaching the positive clamp to the positive terminal of the dead battery first, then the other positive clamp to the positive terminal of the functioning battery.

Step 5: Attach the negative clamp to the negative terminal of the functioning battery, followed by the other negative clamp to any unpainted metal part of your car such as a clean nut or a bolt.

Step 6: Start the functioning car first. Run it for a couple of minutes, then move on to your car. Granted that the transfer of power is successful, your vehicle will turn over easily. For it to continuously recharge, run it for at least 10 minutes.

Step 7: Remove the jumper cables in reverse order once done.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: If the engine dies when you disconnect the jumper cables, check the alternator.

Now, if your car battery won’t hold charge after jump, that means you have a bigger problem in your hands. The culprit could be a faulty ignition switch, starter connection, fuses, alternator, etc. Or, your battery might just be too old and already needs a replacement.

How Long Does It Take to Recharge a Car Battery?

How long it takes to recharge a car battery depends on a number of factors, like the battery and charger type.

If you’re recharging your vehicle’s battery using the vehicle’s alternator, then it might take around thirty minutes’ worth of driving. Instead of letting your vehicle idle during this time, it’s better to drive it, especially if it uses battery-saving measures that might limit its charging ability.

If you use a quick charger on an electric vehicle (EV) battery, it can take as fast as 30 minutes to reach full charge.

External car battery chargers for regular vehicle batteries typically take four to eight hours to fully charge a dead battery. There are also trickle chargers out there that charge slowly with high voltage. They’re mainly for keeping batteries in stored vehicles topped up and healthy.

Picking the Right Charger for Your Car Battery

There are a few different car battery charger types out there, and each has its use.

If you’re looking for something to simply charge up your vehicle’s battery because its alternator is dead, a manual battery charger is a good choice. It won’t turn off on its own or cycle, so you need to closely monitor it when you use it.

Meanwhile, automatic battery chargers will stop charging on their own and switch into maintenance mode as necessary. They’re great for keeping a battery charged up without overcharging or timing the charges.

As mentioned, trickle battery chargers drip-feed a battery power. These are good for stored vehicles. There are trickle battery charge variants that are also automatic.

Finally, you have solar chargers, which connect to solar panels to charge up a vehicle’s battery. Note that these chargers could cause overcharging. So make sure to purchase a charge controller if you plan to leave them connected to your vehicle’s battery for extended periods.

Where to Get a Quality Car Battery Charger

If your car battery dies, it can be a hassle to get your car started again. Using a car battery charger is a good way to fully charge your car’s battery. You can typically leave the charger running and go back to it the next day, which is handy. Even better, you can pick up a quality car battery charger here at CarParts.com.

The CarParts.com catalog has a wide array of aftermarket battery charger brands available for your needs. The battery chargers in our catalog sell for a range of different prices to suit different budgets. Placing an order is quick and easy. It takes just a few clicks to safely buy your chosen products. With our fast shipping services, we’ll deliver your order to your doorstep in as fast as two business days.

Be prepared in case your car battery suddenly conks out. Order a car battery charger at CarParts.com today.

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician